表与表关联 一对多
Posted wangshichang
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1...表与表之间的关系
一对一： A B 两张表 A表中的每条的记录对应的B的一条记录
：一对一关系实现方式：
1：使用外键关联
： 场景：使用客户表和客户拓展表
：在属性上 添加一个@OneToOne代表一个对一个的关系 在属性上添加@JoinColumn? name 存储外键的字段 referencedColumnNm 对方表的字段名称 (可以省略)
2：使用主键关联，两个表 A B 的主键相同。
： 使用@PrimaryKeyJoinColumn 注解不需要配置属性 ?双方都需要添加
一对多： A B 两张表 A表中的每条的记录对应B表中多条的记录 B表中多条的记录对应A表中一条记录
：场景：客户和联系人之间 一对多 ? 一个客户对应多个联系人
：单方：1 添加一个属性 记录多的一方的信息 应该是一个集合 hashset 2 在属性上添加一个注解 @OneToMany 3一定是多的一方记录外键 参照一的一方的主键
：多方：1 在属性上添加 注解 @ManyToOne 2 在属性上添加 @joinColumn 注解
多对多： A B 两张表 A表中的每条的记录对应B表中多条的记录 B表中的每条记录对应A表中的多条记录
：后面补充，
具体实现 ：简单例子
1...pom.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 5 <modelVersion>4.0.0</modelVersion> 6 7 <groupId>com.wsc</groupId> 8 <artifactId>oneToOne</artifactId> 9 <version>1.0-SNAPSHOT</version> 10 11 12 <properties> 13 <spring.version>4.2.4.RELEASE</spring.version> 14 <hibernate.version>5.0.7.Final</hibernate.version> 15 <slf4j.version>1.6.6</slf4j.version> 16 <log4j.version>1.2.12</log4j.version> 17 <c3p0.version>0.9.1.2</c3p0.version> 18 <mysql.version>5.1.6</mysql.version> 19 <maven.compiler.source>1.8</maven.compiler.source> 20 <maven.compiler.target>1.8</maven.compiler.target> 21 </properties> 22 <dependencies> 23 <dependency> 24 <groupId>junit</groupId> 25 <artifactId>junit</artifactId> 26 <version>4.12</version> 27 <scope>test</scope> 28 </dependency> 29 <!--spring start--> 30 <dependency> 31 <groupId>org.aspectj</groupId> 32 <artifactId>aspectjweaver</artifactId> 33 <version>1.6.8</version> 34 </dependency> 35 <dependency> 36 <groupId>org.springframework</groupId> 37 <artifactId>spring-aop</artifactId> 38 <version>$spring.version</version> 39 </dependency> 40 <dependency> 41 <groupId>org.springframework</groupId> 42 <artifactId>spring-context</artifactId> 43 <version>$spring.version</version> 44 </dependency> 45 <dependency> 46 <groupId>org.springframework</groupId> 47 <artifactId>spring-context-support</artifactId> 48 <version>$spring.version</version> 49 </dependency> 50 <dependency> 51 <groupId>org.springframework</groupId> 52 <artifactId>spring-orm</artifactId> 53 <version>$spring.version</version> 54 </dependency> 55 <dependency> 56 <groupId>org.springframework</groupId> 57 <artifactId>spring-beans</artifactId> 58 <version>$spring.version</version> 59 </dependency> 60 <dependency> 61 <groupId>org.springframework</groupId> 62 <artifactId>spring-core</artifactId> 63 <version>$spring.version</version> 64 </dependency> 65 <!--spring end--> 66 <!--hibernate start--> 67 <dependency> 68 <groupId>org.hibernate</groupId> 69 <artifactId>hibernate-core</artifactId> 70 <version>$hibernate.version</version> 71 </dependency> 72 <dependency> 73 <groupId>org.hibernate</groupId> 74 <artifactId>hibernate-entitymanager</artifactId> 75 <version>$hibernate.version</version> 76 </dependency> 77 <dependency> 78 <groupId>org.hibernate</groupId> 79 <artifactId>hibernate-validator</artifactId> 80 <version>5.2.1.Final</version> 81 </dependency> 82 <!--hibernate end--> 83 <dependency> 84 <groupId>c3p0</groupId> 85 <artifactId>c3p0</artifactId> 86 <version>$c3p0.version</version> 87 </dependency> 88 <dependency> 89 <groupId>log4j</groupId> 90 <artifactId>log4j</artifactId> 91 <version>$log4j.version</version> 92 </dependency> 93 <dependency> 94 <groupId>org.slf4j</groupId> 95 <artifactId>slf4j-api</artifactId> 96 <version>$slf4j.version</version> 97 </dependency> 98 <dependency> 99 <groupId>org.slf4j</groupId> 100 <artifactId>slf4j-log4j12</artifactId> 101 <version>$slf4j.version</version> 102 </dependency> 103 <dependency> 104 <groupId>mysql</groupId> 105 <artifactId>mysql-connector-java</artifactId> 106 <version>$mysql.version</version> 107 </dependency> 108 <dependency> 109 <groupId>org.springframework.data</groupId> 110 <artifactId>spring-data-jpa</artifactId> 111 <version>1.9.0.RELEASE</version> 112 </dependency> 113 <dependency> 114 <groupId>org.springframework</groupId> 115 <artifactId>spring-test</artifactId> 116 <version>4.2.4.RELEASE</version> 117 </dependency> 118 <dependency> 119 <groupId>javax.el</groupId> 120 <artifactId>javax.el-api</artifactId> 121 <version>2.2.4</version> 122 </dependency> 123 <dependency> 124 <groupId>org.glassfish.web</groupId> 125 <artifactId>javax.el</artifactId> 126 <version>2.2.4</version> 127 </dependency> 128 </dependencies> 129 </project>
2....applicationContext.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" 4 xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:tx="http://www.springframework.org/schema/tx" 5 xmlns:jpa="http://www.springframework.org/schema/data/jpa" 6 xsi:schemaLocation=" 7 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 8 http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd 9 http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd 10 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd 11 http://www.springframework.org/schema/data/jpa 12 http://www.springframework.org/schema/data/jpa/spring-jpa.xsd"> 13 <!--1 数据源--> 14 <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> 15 <property name="driverClass" value="com.mysql.jdbc.Driver"></property> 16 <property name="user" value="root"></property> 17 <property name="password" value="wsc"></property> 18 <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/shop"></property> 19 </bean> 20 <!--2 工厂类对象--> 21 <bean id="entityManagerFactoryBean" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> 22 <property name="dataSource" ref="dataSource"></property> 23 <!--实体类的扫描器--> 24 <property name="packagesToScan" value="com.wsc.core.entity"></property> 25 <!--配置供应商的适配器--> 26 <property name="jpaVendorAdapter"> 27 <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> 28 <!-- 显示SQL在console 控制台--> 29 <property name="showSql" value="true"></property> 30 <property name="generateDdl" value="true"></property> 31 <property name="database" value="MYSQL"></property> 32 </bean> 33 </property> 34 <property name="jpaProperties"> 35 <!-- create 创建 表 并 更新 每次运行 重新创建 --> 36 <!-- update 创建 表 并 更新 每次运行 在原来基础上 CRUD --> 37 <!-- none 不创建 --> 38 <props> 39 <prop key="hibernate.hbm2ddl.auto">create</prop> 40 </props> 41 </property> 42 </bean> 43 <!--3 事物管理配置配置事物--> 44 <bean id="jpaTransactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> 45 <property name="entityManagerFactory" ref="entityManagerFactoryBean"></property> 46 </bean> 47 <tx:advice id="txAdvice" transaction-manager="jpaTransactionManager"> 48 <tx:attributes> 49 <tx:method name="save*" propagation="REQUIRED"/> 50 <tx:method name="update*" propagation="REQUIRED"/> 51 <tx:method name="delete*" propagation="REQUIRED"/> 52 <tx:method name="add*" propagation="REQUIRED"/> 53 <tx:method name="find*" read-only="true"/> 54 <tx:method name="get*" read-only="true"/> 55 <tx:method name="*" propagation="REQUIRED"/> 56 </tx:attributes> 57 </tx:advice> 58 <aop:config> 59 <aop:pointcut id="pointcut" expression="execution(* com.wsc.core.service.*.*(..))"/> 60 <aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut"></aop:advisor> 61 </aop:config> 62 <!--4 dao的包扫描器--> 63 <jpa:repositories base-package="com.wsc.core.dao" 64 transaction-manager-ref="jpaTransactionManager" 65 entity-manager-factory-ref="entityManagerFactoryBean"> 66 </jpa:repositories> 67 </beans>
3...cities类
1 package com.wsc.core.entity; 2 3 4 import javax.persistence.*; 5 import java.io.Serializable; 6 import java.util.HashSet; 7 import java.util.Set; 8 9 /** 10 * @version 1.0 11 * @ClassName City 12 * @Description TODO 13 * @Author WSC 14 * @Date 2019/8/20 14:18 15 **/ 16 @Entity //实体 必须加 17 @Table(name="ac_city")//表名 18 public class Cities implements Serializable //实现序列化 19 // 配置主键自增的策略 20 @GeneratedValue(strategy = GenerationType.IDENTITY) 21 @Column(name="id") 22 @Id 23 private Long id; 24 @Column(name="cityName") 25 private String cityName; 26 // 表示一对多关联关系 27 @OneToMany(cascade = CascadeType.ALL ) 28 //集合 29 private Set<Flighties> flighties=new HashSet<Flighties>(); 30 31 32 public Long getId() 33 return id; 34 35 36 public void setId(Long id) 37 this.id = id; 38 39 40 public String getCityName() 41 return cityName; 42 43 44 public void setCityName(String cityName) 45 this.cityName = cityName; 46 47 48 public Set<Flighties> getFlighties() 49 return flighties; 50 51 52 public void setFlighties(Set<Flighties> flighties) 53 this.flighties = flighties; 54 55 56 @Override 57 public String toString() 58 return "Cities" + 59 "id=" + id + 60 ", cityName=‘" + cityName + ‘\‘‘ + 61 ", flighties=" + flighties + 62 ‘‘; 63 64
Flighties类
1 package com.wsc.core.entity; 2 3 import javax.persistence.*; 4 import java.io.Serializable; 5 import java.util.Date; 6 7 /** 8 * @version 1.0 9 * @ClassName Flight 10 * @Description TODO 11 * @Author WSC 12 * @Date 2019/8/20 14:26 13 **/ 14 @Entity //实体 必须加 15 @Table(name="ac_flight")//表名 16 public class Flighties implements Serializable //实现序列化 17 @Column(name="id") 18 @Id 19 @GeneratedValue(strategy = GenerationType.IDENTITY) 20 private Long id; 21 @Column(name="flightNo") 22 private String flightNo; 23 @Column(name="arriveDate") 24 private Date arriveDate; 25 // 表示一对多关联关系 26 @ManyToOne //多对一 27 // 外键 name 当前表中外键的字段名 28 @JoinColumn(name="arriveCity",referencedColumnName = "cityName") 29 30 private Cities cities; 31 32 public Long getId() 33 return id; 34 35 36 public void setId(Long id) 37 this.id = id; 38 39 40 public String getFlightNo() 41 return flightNo; 42 43 44 public void setFlightNo(String flightNo) 45 this.flightNo = flightNo; 46 47 48 public Date getArriveDate() 49 return arriveDate; 50 51 52 public void setArriveDate(Date arriveDate) 53 this.arriveDate = arriveDate; 54 55 56 public Cities getCities() 57 return cities; 58 59 60 public void setCities(Cities cities) 61 this.cities = cities; 62 63 64 @Override 65 public String toString() 66 return "Flighties" + 67 "id=" + id + 68 ", flightNo=‘" + flightNo + ‘\‘‘ + 69 ", arriveDate=" + arriveDate + 70 ", cities=" + cities + 71 ‘‘; 72 73
4...dao
CitiesDao类
1 package com.wsc.core.dao; 2 3 import com.wsc.core.entity.Cities; 4 import org.springframework.data.jpa.repository.JpaRepository; 5 6 public interface CitiesDao extends JpaRepository<Cities,Long> 7
Flighties类
1 package com.wsc.core.dao; 2 3 import com.wsc.core.entity.Flighties; 4 import org.springframework.data.jpa.repository.JpaRepository; 5 6 public interface FlightiesDao extends JpaRepository<Flighties,Long> 7
5....test
1 package com.wsc.core.onetone; 2 3 import com.wsc.core.dao.CitiesDao; 4 import com.wsc.core.dao.FlightiesDao; 5 import com.wsc.core.entity.Cities; 6 import com.wsc.core.entity.Flighties; 7 import org.junit.Test; 8 import org.junit.runner.RunWith; 9 import org.springframework.beans.factory.annotation.Autowired; 10 import org.springframework.test.annotation.Commit; 11 import org.springframework.test.context.ContextConfiguration; 12 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; 13 import org.springframework.transaction.annotation.Transactional; 14 15 import java.util.Date; 16 17 18 /** 19 * @version 1.0 20 * @ClassName TestOneTOne 21 * @Description TODO 22 * @Author WSC 23 * @Date 2019/8/20 14:42 24 **/ 25 @RunWith(SpringJUnit4ClassRunner.class) 26 @ContextConfiguration(locations = "classpath:applicationContext.xml") 27 public class OneToMany 28 @Autowired 29 private CitiesDao citiesDao; 30 @Autowired 31 private FlightiesDao flightiesDao; 32 @Test 33 @Transactional //事务 必须加 34 @Commit //提交 必须加 35 public void test02() 36 //创建对象并 赋值 37 Cities cities = new Cities(); 38 cities.setCityName("上海"); 39 //创建对象并 赋值 40 Flighties flighties1 = new Flighties(); 41 flighties1.setArriveDate(new Date()); 42 flighties1.setFlightNo("123"); 43 //创建对象并 赋值 44 Flighties flighties2 = new Flighties(); 45 flighties2.setArriveDate(new Date()); 46 flighties2.setFlightNo("456"); 47 //创建对象并 赋值 48 Flighties flighties3 = new Flighties(); 49 flighties3.setArriveDate(new Date()); 50 flighties3.setFlightNo("789"); 51 52 //加入 对应关系 53 cities.getFlighties().add(flighties1); 54 cities.getFlighties().add(flighties2); 55 cities.getFlighties().add(flighties3); 56 //加入 对应关系 57 flighties1.setCities(cities); 58 flighties2.setCities(cities); 59 flighties3.setCities(cities); 60 //保存 进数据库 61 citiesDao.save(cities); 62 flightiesDao.save(flighties1); 63 flightiesDao.save(flighties2); 64 flightiesDao.save(flighties3); 65 66
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